Mozilla Mail 1.7.1 and 1.7.3, and Thunderbird before 0.9, when HTML-Mails is enabled, allows remote attackers to determine valid e-mail addresses via an HTML e-mail that references a Cascading Style Sheets (CSS) document on the attackers server.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Thunderbird | Mozilla | 0.8 (including) | 0.8 (including) |
| Thunderbird | Mozilla | 1.7.1 (including) | 1.7.1 (including) |
| Thunderbird | Mozilla | 1.7.3 (including) | 1.7.3 (including) |